The present invention relates to a faceting machine for beveling and otherwise cutting gems, precious and semiprecious stones and jewels, both, of the natural and the synthetic variety, but excludes diamonds. Herein the term faceting is to include the grinding, cutting, and polishing of all the facets and of the rond of such such stones, gem, jewels, etc.
The invention is particularly realized by expanding known facet machines, using a multiple jaw collet chuck, a supplemental adapting unit, and by being constructed for purposes of functionally expanding known gem faceting machines which can work on just one gem at the time, such machines are used by both professionals as well as amateures. The inventive gem faceting machine with multiple clamping and holding is expected to exceed the performance of known devices to a considerable extent particularly as far as realizable accuracy of working and functional expansion are concerned, but also with regard to versatility in cutting and grinding, geometry, and ease and comfort of operation, whereby these performance advantages are particularly obtained vis-a-vis single machines using merely mounting pins and driven grinding or cutting wheels or disks.
Moreover, the inventive machine is expected to exceed those which may realize a comparable accuracy in working and cutting, but which can process only one gem at the time. Automatically controlled machines which are provided for holding plural gem mounting pins, and being constructed primarily towards industrial mass production, however, are not comparable to faceting machines constructed in accordance with the invention.
The group or type of gem faceting machines being closely related to the type to which the invention pertains, in that particularly the invention can be regarded as a development and progress over these types of machines, require as a basic characteristic a very careful manual operation, such care being required throughout the entire working process. This manual operation involves particularly manual reciprocating the movable faceting unit across the cutting and grinding wheel or disk in the desired level, further included in these machines features permitting the adjustment of the angle of the respective facets. The working and cutting process progresses from facet to facet whereby the result is visually inspected frequently but is monitored intermittently requiring in each instance a folding up of the working spindle, which, of course, is mounted for rotation.
Aside from standardized or normal types of cuts, these machines should also be capable of cutting and grinding complex geometric patterns for purposes of enhencing brilliance and/or particular ornamental color effects. As far as mounting the gem mounting pins are concerned, these known machines, including those of the type which constitute the point of departure of the invention, have a single working spindle for clamping one mounting pin for a single gem to be bonded thereto. In order to obtain a particular facet pattern, all these machines use the same principle as far as positioning operations are concerned, in that they use wheels which are exchangeable and are either slotted, have gear teeth, or are provided with apertures for latching in well defined positions. This connecting or positioning structure is secured in each instance to the working spindle.
Typically, such a wheel or disk may have 56, 64, 72, 80, 96, or 120 teeth, and a latch is provided which engages any gap in-between any two teeth for arresting and latching the spindle in the particular position. In order to obtain other, i.e. intermediate positions in-between such positions, a nonius kind of fine adjustment is provided for moving the latch in tangential direction to the wheel.
Other known features to be employed are a fork-like support carrying the working spindle within a casing as well as the positioning and switching wheel, the fine adjustment device, and the latch. These elements are pivotable about a horizontal axis and adjustable as far as angular position is concerned between 0 and 90 degrees. This way one obtaines a particular facet angle. The basic arrangement of a working spindle with switching and positioning wheel mounted thereto, latch, and fine adjuster is shown in FIG. 6, as will be explained more fully below. These features are retained by the inventive device. Also, the adjustment of the vertical level, i.e. the positioning in the vertical, particularly in relation to the grinding and cutting wheel is usually effected in most instances by a carriage which can be shifted up and down on a vertical post and carries the entire faceting device. This has been omitted from FIG. 6 but is conventional mounting procedure. German printed patent application 29 34 796 provides for still a different kind of vertical adjustment.
In order to provide an easy indication of the adjusted facet angle which is a secondary angle in relation to the angular adjustment of the working spindle axis with and of the gem mounting axis in relation to the plane of grinding and polishing, a particular patented device has become known being traded under the trademark "H-82 Angleometer" and providing a digital indicating instrument which can be placed separately and independently from the machine for indicating the facet angle.
Another supplementary device has become known through the company Prismatic Instruments of Clayton, Wash., for supplementing known gem faceting machines, wherein a single mounting pin can be clamped in axis-parallel relationship at a selectable distance from the working spindle, and, therefore, eccentrically thereto. The purpose of this supplemental device is to permit cutting and grinding of curved surfaces, preferably at its rond. This pre-supposes that the working spindle, and all parts connected thereto, can be turned to a suitable angle as necessary for obtaining tear drop or shuttle-like peripheral contours.
For working the bottom of a gem or a table cut, requiring that the double pin as a perpendicular position to the grinding and/or cutting disk and plane of rotation thereof, one uses a single pin adapter which, in turn, holds the gem mounting pin at an angle of 45 degrees to the chuck. Such an adapter will thus be inserted into the chuck of the working spindle thereby replacing the regular mounting pin. An accurate perpendicular position of the gem mounting pin which is now placed into the adapter, will be caused with reference to a plane through a 45 degree grag inclination of the working spindle, and in a second position obtained through position of adjustment the positioning wheel as latched and under utilization of the correction provided by the fine adjustment. This permits a chatter-free working and cutting of the gem and ensures proper operation. For inspecting and monitoring the result of working, the entire device can be folded up.
After, either the upper or the underside of a gem has been completed, it is necessary to reposition the gem for working the respective other side very accurately and affix the gem to another mounting pin. Thus, any faceting machine is, in a general sense, associated with such a rebonding device. This device is matched to the particular mounting pin size. Such a re-bonding device is usually comprised of two aligned prisms in which the mounting pins are inserted and fastened. Thereafter, the gem will be bonded with a completed faceted side to a free mounting pin. Following curing of the adhesive, the first used pin on the opposite side is removed.
German printed patent application No. 17 52 070 describes a device for the concurrent facet making on several gems or jewels. By means of this known machine, a common angular adjustment vis-a-vis all gems to be worked on, is supposed to be made possible, particularly in relation to the working tool. This known device includes gem holders or mounting pins, being arranged along the peripheral of a drum and extending radially therefrom. Therefore, in this case, a concentric, i.e. axis parallel arrangement is not provided for. It is believed that this kind of an arrangement does not offer any significant advantage. Moreover, this machine is basically an automated device.
It should be mentioned that German petty patent No. 18 00 614 discloses a different gem faceting machine according to which several gems are cut simultaneously. The mounting pins in this case are arranged one next to the other in particular mounts but this particular publication is not believed to be of any relevance with regard of the approach taken as per the present invention.
The Swiss Pat. No. 446 099 describes an automated gem working machine with a revolver-head-like holder for the mounting pins being, therefore, capable of accommodating several such pins. This patent, however, is again related to an automated tool and differs as far as the present approach is concerned with regard to the objects to be worked on, and the overall construction and function. Moreover, the automated operation is tied to a rather rigid, i.e. inflexible, program and movement of the revolver-head-like mounting pin holder, so that it is believed that this publication is again rather remote from the approach taken in this application.
Various forms of gem and jewel faceting machines with eccentrical mounting as well as with rebonding structures are, by way of example, described and depicted in the following representative publications. Aside from the references already mentioned German printed patent application No. 29 34 796 has to be included as well as the following books:
Herbert Hartig, "Edelsteine und Mineralien selbst schleifen", Verlag Frech, Stuttgart 1967, pages 22-23, 26, 30-31; PA1 Glenn Vargas, "Faceting for Amateurs", published by the authors, Glenn & Martha Vargas, 1969, Library of Congr ess, Catalog Card Number 70-87173, Chapter II, pages 16-24; PA1 Karl Fischer, "Edelsteinbearbeitung", Volumn 1, RuehleDiebener-Verlag, Stuttgart 1985, pages 59-70. PA1 The Lapidary Journal, 3564 Kettner Blvd., P.O. Box 80937, San Diego, Calif. 92138; PA1 April issue 84: PA1 June issue 84: PA1 August issue 84: PA1 September issue 84:
The following papers and journal publications are of interest:
page 52: Faceting unit; Model FAC-8, Imahashi PA2 page 61: American Facetor; ARG Sales Company PA2 page 78: H-82 Angleometer; Alpha Faceting Supply Inc. PA2 page 113: Gem-Master; Fac-Ette Manufact. Company PA2 page 129: Accura-Flex Model H-71A; Prismatic Instruments PA2 page 498: Ultra Tec PA2 page 685; Lee; Lee Lapidaries PA2 page 697: MDR; Master Faceting Instruments PA2 Inside Title page: Mark I, Mark Iv; Graves.
The state of the art, and particularly to the extent as it is related to gem faceting machines, for example, made by Prismatic Instruments and Lee Lapidaries, and others, are disadvantaged by the point that only one gem can be mounted, held, and worked at a time, which is not deemed to be an economical approach. In particular, interruptions and change in the object worked on, being necessary at all times for practical purposes, force the user to employ at least one additional machine, unless he can live with the downtime inherent in object removal and renewal. The removal forces the user to particularly mark the relativ positon of the mounting pin vis-a-vis its holder so that on return the disposition of that pin is exactly reproducable. Still, inaccuracies creep in and the process is time-consuming and cumbersome.
Moreover, certain facet geometries, particularly if they are not of rotational symmetry, cannot be adequately made under mere utilization of the known circle sub-dividing devices and methods, but the aforementioned fine adjustment is necessary to accommodate the non-symmetrical aspects. This, of course, means that upon returning the mounting pin one has to look for the respective facet so as to be able to resume exactly at the point of the interruption. No matter how many aids are used in adjusting, this process is very time-consuming.
Somewhat more sophisticated gem faceting machines attempt to avoid these drawbacks under utilization of mounting pins which have a latched position in the respective clamping structure. That, however, entails other drawbacks. For example, already on bonding the gem to such a pin, one has to anticipate the position of the pin in relation to the latching device after the insertion in the clamping structure. This anticipation is necessary in order to cause agreement and indexing of the reference points for the facet pattern in relation to the reference point on the switch and positioning wheel, and its latching position. also the reference point for the proper disposition of the gem has to be considered in the first place. If the peripheral shape of the gems have been prepared on a different machine or in a free-hand operation the subsequent faceting constitutes, so to speak, the fine finish. In this case, one has to expect deviation between the final facet geometry and the original, raw, peripheral shape. That, of course, entails numerous obvious drawbacks.
Another aspect of the known devices is that to the extent they are eccentrical devices, they exhibit have similar clamping and adjusting problems as described even though these eccentric devices permit cutting of facets which do not have rotational symmetry, the noted drawbacks are factors to be considered. Any accessories for the various gem and jewel faceting machines are closely tied to the particular principal machine for which they are accessories. This includes the rebonding device which, as stated, is comprised usually of two aligned prisms being interconnected. Such accessories also include the latching structure for clamping the mounting pins because these pins themselves are already tied to a particular machine. This means that the axial displacment of the mounting pins is quite limited and that, in turn, makes manipulation and handling more complicated. If one uses mounting pins without latch position then, of course, one again encounters known clamping and adjusting problems during manual intervention.